Clipboard calculator



FIG. 1 is a front right side perspective view of a clipboard calculator, showing my new design;

FIG. 2 is a front plan view thereof;

FIG. 3 is a bottom elevational view thereof;

FIG. 4 is a left-side elevational view thereof;

FIG. 5 is a right side elevational view thereof;

FIG. 6 is a top elevational view thereof; and,

FIG. 7 is a back plan view thereof.

The phantom lines depicting digital numbers in FIG. 2, structures to the underside of the clip in FIG. 6, and the aperture in FIG. 7 illustrate environmental matter and form no part of the claimed design. 

The ornamental design for a clipboard calculator, as shown and described. 